diketahui A dan B merupakan akar akar dari persamaan kuadrat x pangkat 2 + 3x-5 = 0 nilai dari A per B+ B per A

X² + 3x - 5 =0
a = 1
b = 3
c = -5
A + B = -b/a
A + B = -3/1
A + B = -3

A × B = c/a
A × B = -5/1
A × B = -5

• Akar akar persamaan baru :
misalkan :
A/B = X1
B/A = X2

X1 + X2 = A/B + B/A
X1 + X2 = (A²+B²)/AB
X1 + X2 = ((A+B)²-2AB)/AB
X1 + X2 = ((-3)²-2(-5))/(-5)
X1 + X2 = (9+10)/(-5)
X1 + X2 = -19/5

X1 × X2 = A/B × B/A
X1 × X2 = 1

• Persamaan Baru :
X²-(X1+X2) X + (X1×X2) = 0
X²-(-19/5) X + 1 = 0
X²+19/5 X + 1 =0 (Kali 5)
5X²+19X + 5 = 0